Apparatus for casting metal from a container with a sliding nozzle



Dec. 16,1969

ZEHNDER 3,484,026

CONTAINER A. APPARATUS FOR CAST ME L FRO WITH A DI NOZZL Filed Aug. 22. 1967 INVENTOR.

Ame a 252% DER A TT RIVY United States Patent 3,484,026 APPARATUS FOR CASTING METAL FROM A CONTAINER WITH A SLIDING NOZZLE Alfred Zehnder, Baden, Switzerland, assignor to Interstop AG, Zurich, Switzerland Filed Aug. 22, 1967, Ser. No. 662,468 Claims priority, application Switzerland, Aug. 23, 1966, 12,144/ 66 Int. Cl. 365d 47/28, 47/20 US. Cl. 222544 4 Claims ABSTRACT OF THE DISCLOSURE SUMMARY OF THE PRIOR ART This invention relates to an apparatus for casting metals from a container with a sliding nozzle and a discharge opening placed above the sliding nozzle.

In the past, stoppered nozzles have normally been used for controlling the flow of molten metal out of a container. The disadvantages of the stoppered nozzles as compared with the sliding nozzles are well known and therefore it is unnecessary to go into details in this respect.

When casting metals from a container utilizing a sliding nozzle, the out-flowing metal is controlled by displacing a sliding plate having an opening arranged to be disposed below a discharge opening in the container. The sliding plate is moved perpendicularly to the direction of the discharge jet of molten metal.

It is known to arrange a sliding nozzle in the bottom of a container below its discharge opening, to charge the container with molten metal after the sliding nozzle had been closed and to open the nozzle selectively to control the flow of molten metal out of the container. The main disadvantage of such a system arises from the fact that the molten metal penetrates and solidifies within the guiding parts of the sliding nozzle. Since a comparatively long period of time elapses between the charging of the container and the commencement of casting the molten metal is also likely to freeze on the sliding nozzle itself. Consequently, considerable damage may be done to the sliding plate or to the cooperating parts of its guidance mechanism. It is also possible that some of the molten metal may solidify in the discharge opening of the container and obstruct its flow section rendering it impossible to cast metal from the container, even if the sliding nozzle is in a fully opened position.

In the past, this disadvantage was overcome by a device composed of a circular plug or cock adapted to be turned to allow the molten metal to be discharged through a passage in the container and through a hole in the plug. The opening above the circular plug is filled with a small quantity of coal and sand to hold back the metal to be cast from the plug preventing the metal from fouling the operation of the plug. However, the pressure of the molten metal acting at the top of the discharge opening is transmitted through the sand and coal down to the plug. Consequently, by this pressure, parts of the coal are pressed in between the sealing areas of the circular plug and its proper functioning is impeded.

iii)

3,484,026 Patented Dec. 16, 1969 SUMMARY OF THE INVENTION It is the object of the present invention to reduce or to prevent completely the pressure of the molten metal from acting on the sliding plate and to hold back the molten metal from the sliding nozzle.

According to the invention this object is achieved by introducing a plug into the discharge opening, charging the container with the metal to be cast whereby the metal is held back from the sliding nozzle by the plug, opening the sliding nozzle at the commencement of the casting operation and thereafter bringing the metal into contact with and passing it through the sliding nozzle.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.

DESCRIPTION OF THE DRAWING FIG. 1 shows a partial section through a container having a closed sliding nozzle with a flexible plug according to the present invention,

FIG. 2 shows the position of the flexible plug of FIG. 1 after the sliding nozzle is opened, and

FIG. 3 shows a partial section through a container, having a closed sliding nozzle with a rigid plug, disclosing another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawing, FIGS. 1 and 2 show the lower portion of a container 2 which has been charged with a quantity of a low-melting-point metal 71. A sliding plate 5 and its opening 6 along with the sealing parts of the container 2 form a sliding nozzle. A discharge opening 4 is formed in the base of the container above this sliding nozzle. By displacing the sliding plate 5 in a direction indicated by the arrow 11, and aligning its opening 6 below the discharge opening 4 the sliding nozzle is opened. The maximum rate of flow of molten metal is achieved as soon as the opening 6 is in a position which allows the full section of flow of the opening 4 to be utilized. An opening 7 serves to contain and direct the jet of molten metal discharged from the container. A guide mechanism 8 directs the sliding plate 5 between its opened and closed positions and seals off the inside of the container 2 when the sliding nozzle is closed.

Before the molten metal 71 is charged into the container 2, a cup-shaped plug 70, having an outwardly directed flange at its upper open end, is introduced into the opening 4 thereby avoiding any penetration of the molten metal 71 into the guide mechanism 8. If such a penetration of the molten metal took place, the metal would solidify in the guide mechanism 8 thereby making any displacement action of the sliding plate 5 difiicult if not impossible. Also, the disposition of the plug relative to the container walls relieves the sliding plate from the forces which are caused by the pressure of the molten metal 71.

FIG. 2 shows a position of the plug 70 after the sliding nozzle is fully opened. The flexible plug 70 is pressed out of the opening 4 by the pressure of the molten metal 71 thereby bringing the molten metal 71 into contact with the sliding nozzle and enabling it to be discharged from the container 2.

FIG. 3 shows the lower part of a container 2 which has been charged with a high-melting-point metal 1, e.g., steel. Before the metal 1 is loaded into the container 2 a rigid plug is introduced into the opening 4. The plug and the opening may consist of such a form, that the pressure of the molten metal is transmitted to the brick lining of the container 2 thereby relieving the sliding plate 5 from any forces associated with this pressure. Preferably, the material chosen for the plug consists of a material similar to the metal to be cast, whereby the discharge operation is initiated when the sliding nozzle is opened 'by positioning the opening 6 in the sliding plate 5 below the opening 4 and by burning out the plug 90.

Instead of a burning out operation, the plug can be removed and the molten metal can be made to flow out of the container by applying electric heat, such as induction heating, to parts of the plug 90 and the metal 1 in the opening 4.

The scope of this invention is not confined to using plugs as shown in the FIGURES l, 2 and 3. Alternatively, it is possible to apply the method according to the invention by using a plug in the from of a plate, which is supported by the walls of the container at the opening 4. Between such a plate and the sliding plate 5 there should be enough space left to take up the solid parts of the plug and the metal 1, which have originated from the burning out operation and which otherwise would choke the discharge opening. As soon as an adequate flow of molten metal 1 out of the container is built up, the above mentioned solid parts are dragged along with the stream of molten metal.

It is also possible to apply the described method by using a cup-shaped plug, similar to the one shown in FIG. 2, but in an inverted or upside-down position, i.e., its closed end or plate-like member pointing against the metal-side and the open end portion located adjacent to the sliding plate. With such an arrangement enough space is provided to take up the solid parts of the plug and the metal, which may be present after the plug has been burned out.

Further, the method according to the invention does not preclude the application of a plug, which is supported by the sliding plate. The first part of the molten metal 1, which enters the container, solidifies on the top part of the plug thereby transmitting the pressure of the molten metal on to the brick liner. This relieves the sliding plate from the forces associated with this pressure.

Furthermore, the plug may consist of a lower meltingpoint material with a higher specific weight than the metal to be cast or may even consist of two materials.

It will be understood that various changes, alterations and modifications may be made to the illustrated sliding nozzles and plugs without departing from the spirit and scope of the present invention. It is not to be taken as limited except by the appended claims herein.

Also there might be changes in carrying out the method of claim 1. For instance, the first step, according to which a sliding plate is moved to its closed position, can be omitted. This step is preferably carried out for safety reasons. Also this step need not necessarily be carried out before the plug has been inserted into the discharge opening.

What is claimed is:

1. An apparatus for casting metals comprising a container adapted to hold a quantity of molten metal and having a discharge opening in the base thereof, a sliding nozzle incorporating a sliding plate having an opening therethrough disposed within and supported by said container below said discharge opening, said sliding plate being positionable between a closed position for preventing the fiow of molten metal from said discharge opening and an opened position for permitting the flow of molten metal from the discharge opening, a plug being positioned within said discharge opening above said sliding nozzle and forming a seal adapted to maintain the molten metal out of contact from said sliding nozzle, said plug having a cup-shaped configuration and being fitted into the discharge opening of said container with its open end directed upwardly, an outwardly directed flange formed about the open end of said plug and said flange being supported on the walls of said container at the discharge opening therefrom when said sliding plate is in the closed position and said plug being formed of a flexible material whereby when said sliding plate is moved to its open position said plug is adapted to be displaced downwardly from the discharge opening by the pressure of the molten metal within said container.

2. An apparatus for casting metals comprising a container adapted to hold a quantity of molten metal and having a longitudinally extending passage-way extending downwardly from a discharge opening in the base of said container, said passageway having an inlet end at the discharge opening in said container and an outlet end for flowing the molten metal from said container, a sliding nozzle incorporating a sliding plate having an opening therethrough and being arranged in said passageway at an intermediate position between theinlet and outlet ends thereof, said sliding plate being supported by the portion of said container forming said passageway and being positionable in a rectilinear direction transverse to the axis of said passageway between a closed position for sealing said passageway and preventing flow of molten metal from the discharge opening therein and an opened position for flowing molten metal from said container through the discharge opening, means positioned within said passageway between the inlet thereto and said sliding plate for forming a closure for said passageway when said sliding plate is in the closed position to prevent molten metal within said container from passing downwardly through the passageway into contact with said sliding plate and the portion of said container supporting said sliding plate, and said means being imperforate and sufficiently flexible for displacement downwardly through said passageway by the molten metal within said container when said sliding plate is moved to the opened position.

3. An apparatus as set forth in claim 2, wherein said means comprises a member being formed of a flexible material and being arranged to be supported on said sliding plate and extending therefrom upwardly along the surfaces of said passageway whereby the molten metal within said passageway forces said member into contact with the surface of said passageway for preventing the downward flow of the molten metal between the upwardly directed surface of said member and the surface of said passageway.

4. An apparatus as set forth in claim 3, wherein said member being arranged in a cup shaped configuration with the base thereof supported on said sliding plate and the surface of said member forming the opening thereto being supported by said container interiorly thereof from said discharge opening.

References Cited UNITED STATES PATENTS 311,902 2/1885 Lewis 222--561 X 1,007,188 10/1911 Dickson 22Z559 X 1,125,671 11/1915 Durton 164-337 X 1,797,566 3/1931 Brown 164-337 X 2,348,199 5/1944 Freeman 2221 2,883,722 4/1959 Bidner 222559 2,967,339 1/1961 Ma et al. 164-335 X 3,201,837 8/1965 Sylvester 164337 X FOREIGN PATENTS 183,241 7/ 1922 Great Britain. 1,162,032 1/ 1964 Germany.

SAMUEL F. COLEMAN, Primary Examiner US. Cl. X.R. 2225 61 

